Request a live video call during the test drive rather than a pre-recorded one. Cold start first: listen for rattling or metal scraping in the first seconds — possible timing chain or hydraulic lifter issues. During acceleration, a whining from the gearbox area can mean bearing wear; hesitation or jerking in an automatic suggests transmission problems. Braking: the pedal should feel firm, not spongy, and the car must not pull to one side. Turn the wheel fully in both directions and listen for clicking — a classic CV joint fault. Insist on a highway segment too: vibrations above 100 km/h often point to unbalanced wheels or bent rims. Ask the driver to film the dashboard throughout — warning lights that flicker on briefly are still faults that OBD will record.

It's extremely difficult. Unauthorized modifications can lead to module current overload protection, resulting in a lock. In China, you need to use the factory online engineer account to reprogram it. It's basically impossible to perform online decoding overseas. We strongly warn against blindly modifying the electrical systems of modern integrated circuit vehicles.

Interior assessment is divided into three core areas: the driver's high-frequency contact area (steering wheel, gear shift, edge of the driver's seat), central control button area, and rear seats and ceiling. The natural sheen of leather surfaces (patina) is normal; however, any physical damage (such as leather tearing, fabric burn holes, or plastic breakage) will be classified as "structural interior damage" and clearly marked.